Small steps, big leaps – how marram grass builds dunes

The size and shape of dunes varies greatly around the world: in Europe they're tall and narrow, while in the US they're low and wide. A new study has found that this is partly because dunes are constructed by plants with ...

Egyptian crop circles

This week, ESA is focusing on its core Basic Activities, which, for Earth observation, include preserving precious data. Long-time series of datasets are needed to determine changes in our planet's climate so it is vital ...

Arapuca device for international neutrino experiment is enhanced

A critical part of one of the largest recent particle physics experiments was developed in Brazil. The Arapuca is a light detector to be installed in the Deep Underground Neutrino Experiment (DUNE), a project seeking to discover ...

Famous 'sandpile model' shown to move like a traveling sand dune

The so-called Abelian sandpile model has been studied by scientists for more than 30 years to better understand a physical phenomenon called self-organized criticality, which appears in many real-life situations such as the ...

Bird bone streaming

A new website for viewing 3-D bird bones aims to make bird bones in museums more accessible for research and teaching.

Video: Fifteen years imaging the Red Planet

On 25 December 2003, ESA's Mars Express entered orbit around the Red Planet. The spacecraft began returning the first images from orbit using its High Resolution Stereo Camera just a couple of weeks later, and over the course ...

For night vision, snakes see a clear choice

San Diego State University doctoral student Hannes Schraft wanted to learn whether rattlesnakes find their way around at night with their eyes alone, or get an assist from the same thermal-sensing abilities they use to hunt ...

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Dune

In physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a slack. A "dune field" is an area covered by extensive sand dunes. Large dune fields are known as ergs.

Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, the largest complexes of dunes are found inland in dry regions and associated with ancient lake or sea beds.

Dunes also form under the action of water flow (alluvial processes), and on sand or gravel beds of rivers, estuaries and the sea-bed.

The modern word "dune" came into English from French circa 1790. In ancient times, words cognate to "dune" probably had the meaning of a built-up hill or citadel fortification.

This text uses material from Wikipedia, licensed under CC BY-SA